How to Delete Time Machine Local Snapshots on Mac

To delete Time Machine local snapshots on a Mac, list them with tmutil listlocalsnapshots /, then run sudo tmutil deletelocalsnapshots / to remove all of them, or pass a single snapshot date to remove just one. Deleting them doesn’t touch your files or backups. The space they held is “purgeable”: macOS already counts it as available.

TL;DR

tmutil listlocalsnapshots /                              # see what exists
sudo tmutil deletelocalsnapshots 2026-10-22-101530       # delete one (use a date from the list)
sudo tmutil deletelocalsnapshots /                       # delete all local snapshots on the startup disk

• Purgeable space is space macOS can reclaim on its own, mostly snapshots and caches.
• Finder counts purgeable space as available; df and many installers don’t.
• The com.apple.os.update-... snapshot is not a Time Machine snapshot. Leave it alone.

What are Time Machine local snapshots?

When Time Machine is turned on, macOS saves an APFS snapshot of your startup disk about once an hour. According to Apple’s documentation, each hourly snapshot is kept for 24 hours, plus one snapshot of your last successful backup that is kept until space is needed. macOS also saves a snapshot before installing a macOS update.

A snapshot is a frozen view of the disk at a moment in time. It doesn’t copy your files; it keeps the original blocks of any file that has changed or been deleted since. That is the catch for developers: if you delete a 30 GB Docker image or a big DerivedData folder, the snapshot still references those blocks. The files are gone from Finder, but the space isn’t back until the snapshot is deleted.

Other backup apps can create their own APFS snapshots too. Those are managed by the app that created them, not by tmutil.

What does purgeable space mean on a Mac?

Purgeable space is storage that is in use right now but that macOS is allowed to free automatically when an app needs room. On most Macs it is made up of:

• Time Machine local snapshots
• Caches that macOS considers expendable
• Optimized iCloud files whose originals are safely in iCloud and can be downloaded again

Apple’s documentation says your Mac counts the space used by snapshots as available storage. So “available” in Finder means free space plus purgeable space. Terminal’s df reports only truly free space. That is why the two can disagree by many gigabytes, and why a disk can say “45 GB available” while an installer complains there isn’t enough room.

How to see how much purgeable space you have

In Disk Utility

Open Disk Utility, select your startup volume (usually Macintosh HD) and choose File > Get Info. The info window lists “Purgeable space” and “Available space (Purgeable + Free)” alongside free space.

In Terminal

df shows free space without purgeable:

df -h /System/Volumes/Data

To see both numbers side by side, ask macOS the same question Finder asks. This one-liner is read-only:

osascript -l JavaScript -e 'ObjC.import("Foundation"); var r=$.NSURL.fileURLWithPath("/").resourceValuesForKeysError($(["NSURLVolumeAvailableCapacityKey","NSURLVolumeAvailableCapacityForImportantUsageKey"]),null); var f=ObjC.unwrap(r.objectForKey("NSURLVolumeAvailableCapacityKey")), i=ObjC.unwrap(r.objectForKey("NSURLVolumeAvailableCapacityForImportantUsageKey")); "free: "+(f/1e9).toFixed(1)+" GB | available incl. purgeable: "+(i/1e9).toFixed(1)+" GB | purgeable (est.): "+((i-f)/1e9).toFixed(1)+" GB"'

The first number is truly free space. The second is what macOS says is available for important work, which includes space it can purge. The difference is a good estimate of your purgeable space. It is an estimate because macOS decides what it is willing to purge at any given moment.

How to list local snapshots

tmutil listlocalsnapshots /
tmutil listlocalsnapshotdates

The first command lists snapshot names for the startup disk, in the form com.apple.TimeMachine.2026-10-22-101530.local. The second lists just the dates, formatted YYYY-MM-DD-HHMMSS, which is the format the delete command expects. If you see only the header line and no entries, you have no local Time Machine snapshots and they are not your problem.

For a lower-level view that shows every APFS snapshot and whether macOS considers it purgeable:

diskutil apfs listSnapshots /System/Volumes/Data
diskutil apfs listSnapshots /

In Disk Utility, choose View > Show APFS Snapshots to see the same list in a table.

How to delete local Time Machine snapshots in Terminal

Delete one snapshot

Pick a date from tmutil listlocalsnapshotdates and pass it to deletelocalsnapshots:

sudo tmutil deletelocalsnapshots 2026-10-22-101530

Per the tmutil man page, a date deletes the local Time Machine snapshots for that date on all mounted disks. sudo asks for your administrator password.

Delete all local snapshots

Pass a mount point instead of a date to delete every local Time Machine snapshot on that disk:

sudo tmutil deletelocalsnapshots /

Run tmutil listlocalsnapshots / again afterwards to confirm the list is empty.

Thin snapshots instead of deleting them all

If you only need a specific amount of space, thinlocalsnapshots asks macOS to reclaim that many bytes by thinning snapshots:

# Ask for 20 GB back with the highest urgency (1-4)
sudo tmutil thinlocalsnapshots / 20000000000 4

The amount is in bytes and urgency goes from 1 to 4. Use it when you want some space back without wiping every restore point.

How to delete snapshots without Terminal

Two options, both built in:

• Disk Utility. Choose View > Show APFS Snapshots, select the Time Machine snapshots in the list and delete them. Disk Utility warns that the action can’t be undone.
• Time Machine settings. Apple’s documented method is to temporarily turn off automatic backups. In System Settings > General > Time Machine, click Options and set Backup Frequency to Manually, wait a few minutes for macOS to remove the local snapshots, then set it back to automatic. Don’t forget the last step, or you’ll stop getting backups.

Should you delete Time Machine local snapshots?

Usually you don’t need to. macOS deletes snapshots as they age or when space is needed, and Apple’s documentation says snapshots don’t use space needed for tasks like downloading or copying files.

There are good reasons to delete them anyway:

• A tool checks real free space. Some installers and command-line tools check free space, not available space, and fail even though macOS would free the room if asked.
• You just deleted something big. After removing a large Docker image, simulator runtime or build folder, the space stays referenced until the snapshots that hold it expire or are thinned. Deleting them gets it back now.
• You need accurate numbers. When you are trying to see what is really using your disk, snapshots blur every measurement.

The cost is small: you lose the hourly restore points stored on your Mac. Your backups on the backup disk are not affected.

Snapshots you should not delete

Run diskutil apfs listSnapshots / and you will likely see a snapshot named com.apple.os.update-... marked “Purgeable: No”. That is the snapshot of the sealed system volume your Mac boots from, created by macOS updates. It is not a Time Machine snapshot, tmutil doesn’t manage it, and you should not try to remove it.

Snapshots made by third-party backup apps are best removed from inside those apps, so their own records stay consistent.

Why purgeable space comes back

Local snapshots are created about every hour while Time Machine is on, so the purgeable number climbs again after you delete them. That is expected. If you need the space permanently, the fix is to delete the data that keeps generating large snapshots, which on a developer Mac means build output, Docker data and caches. Our guides to Mac System Data and Library caches cover those.

Do it in one click with DevCleanup

DevCleanup’s System Data screen lists your Time Machine local snapshots with their dates and deletes the ones you pick using the same tmutil deletelocalsnapshots command, after macOS asks for your administrator password. It also shows how much space is purgeable. The other half is the large, rebuildable data that keeps snapshots and System Data growing: Smart Clean clears caches, logs and Xcode DerivedData, and the Simulators, Docker and Projects screens handle the biggest developer folders. Every action is logged in History.

Download DevCleanup. Scanning is free; Pro ($29 one-time) unlocks the developer cleanup actions. For the full checklist, see how to free up space on Mac as a developer.